Stoker



Patent ed Apr. 12, 1927.

UNITED STAT Es. PATENT I nnnc'rmoann I ACIUBING COMPLNY,,.A CORPORATION OF PENNSYLVANIA.

STOKER.

Application and June 4', 1923. Serial summer. I invention relates to multiple retort underfeed stoker furnaces in which fuelfeeding retorts and rows of tuyeres are alternatel arranged n Parallel relation" and mcline downwardly from the front wall of the furnace, and it has for an object to provide in a, furnace of the character designated a means for introducing into the green fue entering the furnace a supply of highly heated airfor the fuel ignition.

Another object of my invention 1s to provide in a furnace of the character designated a durable-front wall construction including means for defining the fuel openings be- Y tween the ram boxes and the retorts and for 'suppo the refractory front wall of the furnace a ove the fuel openings. A further object of my invention is to provide for the circulation of air from the. tuyere air boxes of the 'stoker furnace.

through the wall structures defining thefuel openings into the retorts for the ual purpose o cooling the wall members and of pre-heatin the air for assisting in the 1gnition of e enterin fuel.

A still further ob ect of my invention is 1 to provide a front-wall air-box construction for distributing air pre-heated' in the wallsupporting structures to the entering fuel and to the combustion zones of the furnace.

These and other objects of my invention are attained by meansof a stoker const ruc tion embodyin the features herein described and illustraterf in the drawings accompanying and forming a part hereof wherein:

Fig. 1 is a fra mentary view in longitudinal sectionv of t e front end of an underffeed stocker furnace embodyin my invention, taken on the line II of ig. 3; Fig. 2 is a fragmentary view in longitudinal section taken on line IIII of Fig. 3;

Fig. 3 is a fragmentary view, in part in transverse section taken on the line III-III of Fig. 1, and in part in elevation looking at the front wall from the interior of the furnace;

Fig. 4 is a view from the interior of the furnace of one of the hollow wall supporting casing, showing the openings for the ingress and egress of air; and,

' the air distributing purpose of facilitating supported at the front of the Fig. 5is a view boxes. Referring now to the drawing, I show a portion of an underfeed stoker com osed of a plurality of retorts 11: and tuyere anks 12. The tuyeres=13 of the tuyere banks 12 are mounted upon the upper edges of side walls 14 of the retorts 11 which walls'define with the tuyeres air boxes 15. The reangle beams 18 which exten length of the underfeed grate and which in turn are furnace by the castings 19. The castings 19 preferably have spaced recesses 21 and lugs- 22 therebeneatli for positioning and carrying in elevation of one of to tort side-walls'14 maybe suplported upon.

the angle beams 18-. Lateral projections 23 i at the ends of the castings 19 serve, when a plurallty of sections are assembled, to provide a As s own in igs. 1 and 2 of the drawing,

the angle. beams'18 project forwardly from roper s acing of the retort elements.

the castings 19 and carry ram boxes 25 which have hopper openings 26 and fuel delivery orifices 27 The retorts 11 may have bottom plates 28 and coal deflector plates 29 of conventional construction.

Westinghouse Electric and Manufacturing Company.

Mounted upon supportin castings 30, one casting 30 being disposed etween each pair of retorts. The castin 30 are of T-shaped conformation, the ho low pedestals 31 of the casting having openings 32 for thein ressof air and the hollow cross arms 33 avin openings 34 for the discharge of air. bled with other parts of the stoker the cross arms of the T-castings 30 abut and form a table 35 upon' which the refractory portion ifih of the front furnace wall is supported.

c with the retort registering with of the ram boxes 25. The castings 30 further form closures for the forward ends of elements fuel openings 38 the lateral extensions 23- of the abutting castings 19 are hollow wall.

it en assem the fuel delivery orifices 27 The above described stoken construction V 119, filed May 10, 1923 and assigned to the pedestals 31 of the T-castings define Y the tuyere air boxes with which the air chambers within the castings 30 freely com- 'municate through the open ngs 32.

Removable front 'wall' air-distributing boxes 40 are disposed rearwardly of and when assembled abut one another as shown in Fig. 3; Tuyere openings 45 in the cross arms 43 and tuyere' openings 46 in the feet of the air-distributing boxes 40 are provided for the distribution of air within the furnace. It may be desirable in furnaces in which fuels having hi or fuels which ignite on y with difiiculty are employed, to omit the openings 45 in the cross arms 43 and to direct all the pre-heated gir through the openings 46 into incoming uel.

The manner in hich the above described invention may be practiced is briefly as follows: In the construction of the front furnace wall, the forward end of the stoker grateis supported upon castings 19 which carry the angle beams 18 and the side plates 14. The lateral extensions 23 of the adjacent castings 19 are disposed at the forward. ends of the tuyere air boxes 15 and serveas bases upon which the hollow wall supportingT-castings 30 are mounted. The T-castings are disposed along the front of the furnace, one;

etween eachpair .of retort s, and form a table 35 upon which the refractory front wall 36 of the furnace is carried. The castings 30 form closures for the forward ends of theair boxes 15 and receive air therefrom through the openings 32. The

air circulates upwardly through the pedestals 31 into the cross arms'33 of the .T-castings and passes out through the openings 34 into the cross arms 43 of the air-distributing boxes 40 where a part of the air may escape through the openings '45 into, the furnace. The major portion of the preheated air should, however, preferably pass downwardly through the pedestals 41 and into the incoming fuel bed through the openings 46.

It is to be understood that the fuel from the ram boxes 25 is forced into the furnace through openings 38 and is distributed into the retorts and over the tuyere banks in the usual manner. It is apparent that theupper layers of green fuel upon entering the furnace are subjected to the blasts of-the highly heated air from the openings 46 of the air-distributing box 40. The surface layers of the entering fuel, being thus subjcctcd to a blast of heated air, are readily ignited. This is especially advantageous in furnaces burning fuels which ignite with the castings 30 and h moisture content further advantage of forming a rigid and durable furnace front wall, since the wall castings 30 rest uponthe castings 19 and hence the retort elements, which at times need to be replaced, are free of the weight of the front wall and consequently may be removed without disturbing the front wall construction. Further, the circulation of air through the wall supporting castings maintains these members at a moderate temperature and cuts down any excessive expansion or contraction of these members under changes of furnace temperature. The refractory. ortion of the front wall is for this reason su jected to lesser lifting strains and is therefore capable of giving longer service.

While I have shown my invention in but one form, it may be obvious to those'ski (1 iii the art that it is not so limited, but is susceptible of various changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall'be placed thereupon as are imposed by' the prior art or as are specificaly set forth in the appended claims.

What I claim is: I

1. In an underfeed stoker furnace in which the side walls ,of spaced retorts carrytuyere members and define therewith air boxes alternating with the retorts, hollow castings closing the forward ends of the air boxes and formed to conduct air therethrough,and-

tort, hollow castings defining fuel openings from the ram boxesinto the retorts, and air distributing members disposed rearwardly of the .said hollow. castings, said hollow castings and air distributing members being formed to conduct air therethrough and to the furnace.

3. In an underfeed stoker furnace in which the side wallsof spaced retorts carrytuyere members and define therewith air boxesal ternatingwiththe retorts, hollow castings supporting the front refractory wall of the furnace and defining fuel openings into the retorts, and air distributing members disposed rearwardly of said hollow castings each provided with an expanded foot ortion having air port-s therein, said he low castings and air distributing members being formed to conduct air therethrough to the incoming fuel.

- 4. In an underfeed stoker having a fuel supporting surface comprising alternating series of tuyeres and retorts and) air boxes an I below the tuyeres and between the retorts, boxes and receive air therefrom, and dis castings at the forward end of the furnace tributing members on the sides of the holsupporting the retorts, hollow castings low castings adjacentthe retorts. p v 10 mounted upon the retort supporting cast- Intestimony whereof, I have hereunto 8 ings to support the front refractory wall of subscribed my name this' 29th day oi May the furnace, said hollow castings being so 1923. I positioned as to close the ends of the air OTTO 

